Abstract: The design principle,system architecture and key functions of ZD-AFRS,a robust and hybrid machining feature recognition system,is presented.To make ZD-AFRS both advanced and practical,following measures are taken in developing it.Reliable algorithms for dealing with split faces,merged faces and virtual links are devised to improve the robustness of automatic feature recognition function；interactive feature recognition is integrated with automatic feature recognition to enable the system practical；user-defined feature capability is developed to make the system extendable； functions of volume feature generation,reasonable feature interpretation determination and automatic stock generation are provided to get the system complete.Tested by many samples,ZD-AFRS shows good robustness and practicability.